Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Topic Last Modified: 2011-03-19

The Recipient Filter agent is an anti-spam agent that is enabled on Edge Transport servers. You can use the Recipient Filter to block incoming messages for specific recipients in your organization. You can also block incoming messages to recipients that do not exist in Active Directory.

This topic explains how to use the EMC or the Shell to add recipients to the list of blocked recipients.

Note:
Recipient filtering is part of the suite of anti-spam features in Exchange. The anti-spam features are only available on Edge Transport servers by default. You can enable anti-spam features on a Hub Transport server even though it isn't recommended. To learn more about enabling anti-spam features on a Hub Transport server, see Enable Anti-Spam Functionality on a Hub Transport Server. The procedures listed in this topic are for configuring anti-spam functionality on an Edge Transport server, but the process is identical on Hub Transport servers.

What Do You Want to Do?

Use the EMC to configure recipient filtering

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Anti-spam features" entry in the Transport Permissions topic.

  1. In the console tree, click Edge Transport.

  2. In the result pane, click the Edge server you want to configure and then select the Anti-spam tab in the work pane.

  3. Right-click Recipient Filtering and then select Properties.

  4. The General tab displays the following information about the recipient filtering feature.

    • Status   Shows whether recipient filtering is enabled or disabled.

    • Modified   Shows the date and time when recipient filtering properties were last modified.

    • Description   Provides a brief description of recipient filtering.

  5. Use the Blocked Recipients tab to maintain the Recipient Block list, an administrator-defined list of up to 800 recipients for which incoming messages from the Internet should never be accepted.

    • Block messages sent to recipients that do not exist in the directory   To prevent delivery to recipients that aren't in the organization's global address book, select this option. This feature is maintained through the EdgeSync process.

    • Block messages sent to the following recipients   To create an administrator-maintained list of recipients that should be blocked from receiving messages from the Internet, this option, type the SMTP address for the recipient, and then click Add. You can enter up to 800 recipients.

      To change an existing recipient address, select the address and then click Edit.

      To remove an existing recipient address, select the address and click Remove icon.

Use the Shell to configure recipient filtering

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Anti-spam features" entry in the Transport Permissions topic.

You use the Set-RecipientFilterConfig cmdlet to manage recipient filtering. The following example configures the Recipient Filter agent to block specific recipients:

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Set-RecipientFilterConfig -BlockListEnabled $true

To add SMTP addresses to the Recipient Block list, you use the BlockedRecipients parameter of the Set-RecipientFilterConfig cmdlet. You can separate multiple SMTP addresses with commas. The following example adds the e-mail addresses mark@contoso.com and kim@contoso.com to the Recipient Block list:

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Set-RecipientFilterConfig -BlockedRecipients mark@contoso.com,kim@contoso.com

The values that you specify by using the BlockedRecipients parameter replace the existing list of SMTP addresses. To preserve the existing list, you could specify the existing addresses along with new addresses you want to add. However, this can be a cumbersome task especially if you have many SMTP addresses for which you block incoming messages. Instead, you can use a temporary Shell variable to add an address to the Recipient Block list. The following example uses the temporary variable $Configuration to add the SMTP address john@contoso.com to the Recipient Block list:

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$Configuration = Get-RecipientFilterConfig
$Configuration.BlockedRecipients += "john@contoso.com"
Set-RecipientFilterConfig -BlockedRecipients $Configuration.BlockedRecipients

To block messages to recipients that don't exist in your organization, run the following command:

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Set-RecipientFilterConfig -RecipientValidationEnabled $true

For detailed syntax and parameter information, see Set-RecipientFilterConfig.